BOP stack

Company / operator legend practice (API 6A, API 521, API 537) / PIP PIC001 (API 16A / 53)

Drawn as

A vertical stack: an annular preventer on top (a rounded block), then two or three ram blocks (rectangles with rams drawn as opposing filled triangles), with choke and kill side outlets and valves.

Meaning

Blowout preventer stack on the wellhead during drilling and workover. Becomes bop-stack; the side outlets go to the choke & kill manifold (choke-manifold).

Variants

Ram types are written beside each block (pipe, blind, shear)